Kidney stones are one of the worst non-lethal medical problems that can happen to a human, causing fever, exhaustion, and the excruciating pain that comes with trying to literally pee out a very tiny but very sharp rock. And the condition is painfully common: one in ten people will experience a kidney stone at some point in their lives, most often during young adulthood, according to the National Kidney Foundation. But two enterprising doctors have come up with an effective and entertaining way to deal: Roller coasters!
Like many scientific discoveries, this one started with a happy accident. David D. Wartinger, D.O., J.D., and his colleague at the University of Michigan, Marc Mitchell, D.O., say that 10 years ago a patient reported having passed three separate kidney stones after riding a particular roller coaster three separate times. And he wasn't the only one. Over the years, other patients reported similar effects from roller coasters, bungee jumping, and other types of motion-driven rides. It happened enough times that the doctors began to wonder if there was some therapeutic value for kidneys in coaster riding. So they did what any ride-lover would do and headed to Disney World to test their theory out. They packed an artificial silicone kidney with real kidney stones and urine and hopped on the Big Thunder Mountain Railroad. Twenty rides later—"It was a terrible burden," Wartinger jokes—they had their answer. (Related: Is it bad to hold your pee?)
Riding a roller coaster really can jostle a kidney stone loose, they reported in a new study published in the Journal of the American Osteopathic Association. But when it comes from moving a stone out of the kidney and into the ureter where it can be passed, "jostle" is the key word, Wartinger explains in a video accompany the paper. Sitting in the front row of the coaster only managed to dislodge four out of 24 stones. However, sitting in the back of the coaster, where the motion was more intense, worked out 23 out of 36 stones.
But it doesn't have to be the scariest roller coaster to get results, Wartinger reassures. "It's all about the quick drops and sharp turns," he says, adding that the Big Thunder Mountain Railroad coaster doesn't exceed 40 miles an hour or go upside down.
Riding the rides also acts as a preventative for people prone to getting kidney stones. "Periodic roller coaster riding may dislodge renal calculi [stones] before they reach obstructive size," he explains. This, he adds, can help reduce pain associated with the stones along with the need for medication, dietary restrictions, and even surgery.
Sick day in Disney World, anyone?